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What would cause an ATS46 to trip and display InF (Internal Fault)?

Published date: 18 February 2019

What would cause an ATS46 to trip and display InF (Internal Fault)?

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Customer had an ATS46 tripped on InF fault.

-Bad internal connections (verify all are secure)
-Rating not recognized
-Check the time sequence of the shorting contactor dropping out. Possibly either no time delay or shorting contactors arced causing internal fault (possibly stopping the motor by dropping out isolation contactor)
-If have another unit, try swapping control baskets to see if issue stays with the basket or the unit

***Additionally, ATS46 units manufactured prior to the 46 week of 2001 (or a date code of 0146) had a control board component that might fail prematurely resulting in an unrecoverable Internal Fault. Replacing the control board will resolved that.

****If ATS23 in MCC have seen this occur in bypass which is normal for that setup because the CTs are seeing current passing through them, but it is not being told to run and thus get this fault (have to cycle power to reset)

Note: ATS46 soft starts have all been obsoleted, with no replacement parts..  Suggest to replace with a ATS48 soft start.

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